Bunk bed



FIG. 1 is a front, left perspective view of an example embodiment of a bunk bed of my new design;

FIG. 2 is a front, side view of the bunk bed of FIG. 1;

FIG. 3 is a rear, side view of the bunk bed of FIG. 1;

FIG. 4 is an end view of the bunk bed of FIG. 1; and,

FIG. 5 is top view of the bunk bed of FIG. 1.

The broken lines in the drawings illustrate portions of the bunk bed that form no part of the claimed design. 

CLAIM The ornamental design for a bunk bed, as shown and described. 